Since most electric power for a display device that is provided with a backlight is consumed by the backlight, power consumption of the display device is reduced by reducing power consumption of the backlight.
Under the circumstances, in recent years, known is a display device which has a CABC (Contents Adaptive Backlight Control) function which controls a backlight in accordance with an image so as to reduce power consumption of the backlight.
For example, as illustrated in FIG. 7, an image display device, disclosed in Patent Literature 1, includes (i) a light modulating value deciding circuit 113 for deciding a light modulating value for a backlight 117 on the basis of an input image signal, (ii) an image signal correcting circuit 120 for correcting, in accordance with a light modulating value, an input image signal to be supplied to a liquid crystal panel 122, and (iii) a backlight driving circuit 116 for controlling driving of the backlight 117 in accordance with a light modulating value. The backlight driving circuit 116 delays timing at which a light modulating value for a current frame is applied, in a case where a luminance of the backlight 117 during the current frame is higher than that of the backlight 117 during the previous frame. This makes it possible to alleviate a deterioration in image quality and reduce power consumption of the backlight 117, even in a case of a rapid change in luminance of an image displayed on the liquid crystal panel 122 while the luminance of the backlight 117 is being controlled.
Further, for example, a conventional configuration, illustrated in FIG. 8, is known. FIG. 8 is an exploded perspective view illustrating a large-sized display device having the conventional configuration. The display device, illustrated in FIG. 8, is a relatively large-sized display device including a plurality of source drivers which enable the display device to display an image in a display region 131 of a liquid crystal panel 125.
Most conventional display devices include a timing controller 123 illustrated in FIG. 8. A typical timing controller (i) receives an externally supplied video signal, (ii) analyzes an image, (iii) generates a control signal (PWM signal) on the basis of a result obtained by analyzing the image, and (iv) supplies the control signal to a backlight driving circuit. The typical timing controller further (i) functions to convert the externally supplied video signal into a signal which allows each source driver to supply a voltage to signal lines with a minimum circuit configuration, and (ii) supplies the signal to the each source driver.
The timing controller 123, which is included in the display device illustrated in FIG. 8, (i) controls timings at which a gate driver 121 and a plurality of source drivers 130-1 through 130-3 are driven, and (ii) supplies pixel data stream to the plurality of source drivers 130-1 through 130-3. The timing controller 123 generates a PWM signal 125, and supplies the PWM signal 125 to a backlight driving circuit 136 for controlling a backlight unit 137.
The timing controller 123 is a circuit provided on a timing control substrate.
On the other hand, recently, display devices including no timing controller (timing control substrate) have been developed.
FIG. 9 is an exploded perspective view illustrating how a conventional small-sized display device is configured. The small-sized display device, illustrated in FIG. 9, includes a liquid crystal panel 150 and a backlight unit 167. The liquid crystal panel 150 includes one (1) source driver 153 and one (1) gate driver (not illustrated). The gate driver can be monolithically configured on a glass substrate of a display panel. Upon reception of a video signal, the source driver 153 analyzes an image, generates a PWM signal 156 on the basis of a result obtained by analyzing the image, and then supplies the PWM signal 156 to a backlight driving circuit 157. That is, the source driver 153 serves as a timing controller.